Universal Mini Chassis (UMC): Versatile Inlet Options & Rifle Compatibility in One Modular Platform

Unlock Versatility with the Universal Mini Chassis (UMC)

Grayboe’s Universal Mini Chassis (UMC) revolutionizes stock modularity. Crafted for use in the Flagstaff, Core, and upcoming Renegade 2 stocks, the UMC lets your rifle bolt directly onto the chassis, which then fits into the stock—making it easy to swap rifles or calibers without changing the entire stock.

What Inlet Options Are Available?
- Short or Long Action Compatibility
The UMC supports both short- and long-action rifles—no matter the brand—enabling you to use short-action Remington or long-action Howa rifles interchangeably.

- Optional Adjustable Magazine Release Lever
Customize your magazine feeding with a paddle-style release lever (available on most UMC models). This adjustable lever gives up to 0.080″ of vertical magazine height adjustment for optimal functionality.

- Standard AICS Magazine Compatibility
The UMC is designed to accept AICS-style detachable magazines, ensuring smooth and reliable feeding—without needing additional bottom metal.

Compatible Rifles—Plug and Play Across Platforms
No matter your rifle's origin, if Grayboe provides a matching UMC inlet, it will fit:

Remington – short and long actions supported

Example: Remington 700 .7PRC (long action) can be paired with its UMC and interchanged with other rifles.

Howa – short/long action compatible as long as a UMC exists for that model.

Ruger American & Mossberg Patriot – these models require the rifle to be bolted to the UMC prior to inserting into the stock, but are fully supported.

Why It Matters: Benefits of the UMC System
- Modular Flexibility
Swap rifles and calibers within a single stock for streamlined logistics—ideal for diverse hunting or range needs. 

- Repeatable Zero
Once sighted in, your rifle retains zero even when the UMC is removed from the stock—thanks to the chassis maintaining alignment.

- Durability & Precision
The UMC is crafted from T6 6061 billet aluminum—hard anodized or Cerakote finished—ensuring rugged durability and consistent fit.

Summary Table
Feature	                    Description
Compatible Stocks	    Flagstaff, Core, Renegade 2
Rifle Platforms Supported   Remington, Howa, Ruger American,                             Mossberg Patriot (if UMC available)
Action Types	            Short action, Long action
Optional Feature	    Adjustable paddle-style magazine                             release lever (0.080″ adjustment)
Magazine Compatibility	    AICS-style detachable magazines
Materials & Finish	    T6 6061 billet aluminum, hard-                            anodized or Cerakote
Zero Retention	            Holds zero even when removed from                             stock